Senior Frontend Engineer (Pass) en Barcelona, España

Join Proton and build a better internet where privacy is the default

Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right. Since then, we've built the world's largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and Proton Calendar-tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some situations, Proton has literally helped save lives!

We are profitable, independent (no VC control), and selectively hire from the top ~1% of applicants. Our 500+ team members across 50+ countries come from leading organizations and elite academic backgrounds. We move fast, keep hierarchy light, and prioritize impact over optics. If you want to do meaningful work with exceptionally high-caliber people, this is it. Join us and do work you can truly be proud of. Check our open-source projects here!

We're seeking an experienced developer working across multiple web platforms including browser extensions, web and desktop applications. This role requires both front-end expertise and deep technical knowledge of browser internals, extension APIs, and desktop application frameworks

• Develop new features: Developing, deploying and supporting high-quality user experiences, including feature development and implementation.
• Collaboration: Work closely with backend, product owners, designers, QA, and other engineers to take initiatives from ideation to completion. Break down large initiatives into smaller milestones to gather stakeholder feedback quickly.
• Code review and optimization: Conduct code reviews and provide constructive feedback to ensure code quality, maintainability, and performance optimization.
• Testing: Develop and implement comprehensive testing strategies, including unit tests and end-to-end testing tests, to ensure the reliability of the Proton Pass product.

• Experience with modern MV3 browser extension development.
• Experience with Electron or similar desktop application frameworks.
• Experience with browser extensions and/or cross-platform web applications.
• Experience working with service-worker architectures.
• Experience with WebAssembly and/or Rust.
• Experience with breaking down product requirements into architecture design and implementation.
• Experience with event-driven systems.
• Familiarity with UX, accessibility and localization concerns.
• Experience with application monitoring strategies.
• High-level understanding of cryptography concepts such as key exchange and the difference between symmetric and asymmetric encryption.

• Work that Matters: millions of people trust Proton with their privacy. We answer only to our users - not advertisers, not investors with conflicting agendas, not governments. The work you do here is real, and the impact is measurable. (here)
• A great Team: Our team is diverse, collaborative, and tight-knit with people coming from all walks of life, including many of the world's top academic institutions and organizations, such as MIT, Harvard, Stanford, Caltech, Cambridge, and ETH.
• Technology: you'll get the right hardware and the right software you need to do your best work.
• Learning & Development: we invest in your growth because sharp people make us better. Proton is one of the fastest ways to accelerate your career because you'll be thrown into real challenges, with real ownership, from day one.
• Employee Benefits: your wellbeing isn't an afterthought. We offer strong health coverage, solid retirement options, generous leave, and wellness support so you can bring your best self to work every day
• Stock Options: at Proton, we all have the opportunity to be owners of the company. From day one, you have a real stake in what we're building. When Proton wins, you win.
• In-Person Collaboration: Amazing things happen when passionate, smart, and purposeful people get together in the same room. With offices across Geneva, Zürich, Barcelona, London and more, you'll spend most of your time collaborating face-to-face with people who genuinely care about what they're building
• Food: Lunch and snacks are on us every day in our offices so you can focus on the work and not on what's for lunch.
• Transport: getting to the office shouldn't cost you. We cover public transport, bike allowances, or parking, whichever works for you.
• Flexible Working: you own your schedule. Set hours that work for you and your team - because outcomes matter more than when the clock says you started.
• Paris: 54,000 - 106,000 EUR gross annually*
• Barcelona: 53,000 - 104,000 EUR gross annually*
• Final compensation will be determined based on the candidate's qualifications, skills, and previous experience.

Proton Pass is a secure, open-source password manager developed by Proton-the team behind Proton Mail and Proton VPN. Built with end-to-end encryption and a strong commitment to privacy, Proton Pass helps individuals and teams safely manage passwords, 2FA codes, notes, and more. As part of the Proton ecosystem, it integrates seamlessly with other privacy-first tools, ensuring robust protection for your digital identity.

• Proven front-end expertise with deep technical knowledge of browser internals, extension APIs, and desktop application frameworks.
• Deep understanding of the Javascript ecosystem.
• Proficiency with TypeScript or type-safe programming paradigms.
• Strong understanding of software engineering best practices, Design patterns, CI/CD.
• A product mindset with a focus on offering the best user experiences.
• Experience working in a distributed team.

At Proton, we believe diversity drives innovation and strengthens our mission to provide privacy as a default for all. We are committed to fostering an inclusive environment where all individuals, regardless of race, ethnicity, gender, age, sexual orientation, physical ability, or socio-economic background, feel valued and empowered. We strive to create equal opportunities, promote open dialogue, and support continuous learning to ensure every voice is heard and respected.

If you need any extra support or reasonable adjustments during the hiring process, please let your talent partner know.

When you apply for a position, refer a candidate, or are considered for a role at Proton Technologies AG (Proton, we, us, or our), your information is stored in Greenhouse, in accordance with their Service Privacy Policy. This information is used to evaluate your suitability for the posted position. We also retain this information for consideration for future roles that you may apply for or that we believe may align with your background and skills.

If we no longer have a legitimate business need to process your information, we will either delete or anonymize it. Should you have any inquiries about how we use or manage your information, or if you wish to access, correct, or delete your data, please contact our privacy team at [email protected].

Proton does not accept unsolicited resumes from any sources other than directly from candidates. We will not pay a fee for any placement resulting from an unsolicited offer, even if the candidate is subsequently hired by Proton.

To learn more about our privacy policy, please visit our privacy policy page.